French is the language of France and of many other countries, and the adjective for France and its people. It takes a capital letter, always.
It appears in a long list of English compounds that describe things the French would not recognise: French windows, French plait, French bread, French dressing, and French fries, which Belgium disputes. That pattern of naming foreign-seeming things after France is old and mostly affectionate. The people collectively are the French; a single person is a Frenchman or a Frenchwoman, and there is no neat neutral singular, which is why French person is what most writers now use.
1nounlanguageThe language of France.
“She learned French at school and forgot most of it.”
2adjectivefrenchBelonging to France or its people.
“There is a French bakery on the corner.”
3nountakenThe people of France, taken together.
“The French take August seriously.”
Too few real examples of this word to estimate which sense is commonest.
french is a language or nationality.
Old English Frencisc meant of the Franks — the Germanic people who gave their name to France after settling in Roman Gaul. So the name of the most famous Romance language comes from a Germanic tribe, and English is one of the few languages that still shows the join.
Old English
Frencisc — of the Franks, Frankish, French
Middle English
French
English, today
french
Built from
From Middle English French, Frensch, Frensh, from Old English Frencisc (“of the Franks, Frankish, French”), from Franca (“a Frank”). Compare Old High German Franko (“a Frank”), akin to Old English franca (“javelin, spear”), from the use of such weapons by the Franks.
Etymology from Wiktionary, CC BY-SA